---
title: 'Senior Accountant at Mariana Minerals'
canonical: 'https://feeny.ai/job/senior-accountant-mariana-minerals-houston-r5syam2x663j'
type: 'job'
last_seen: '2026-09-11'
---

# Senior Accountant at Mariana Minerals

- **Company:** Mariana Minerals
- **Location:** Houston, TX
- **Compensation:** $90k–$126k
- **Employment:** full-time
- **Work type:** hybrid
- **Posted:** 2026-08-12
- **Last confirmed live:** 2026-09-11
- **Apply:** https://jobs.ashbyhq.com/marianaminerals/73152a81-4553-4552-9408-71c5f07a3798

## Job description

## About Mariana Minerals

Mariana Minerals is a software-first, vertically integrated minerals company on a mission to supply the critical minerals powering modern energy, AI, and defense technologies. We’re reimagining the minerals supply chain by combining deep industry expertise with advanced software, automation, and data-driven decision-making.

## The Role

We are hiring a Senior Accountant to support the accounting operations that ensure accuracy, transparency, and reliability across Mariana’s growing portfolio of assets and operating entities. This is a hands-on role focused on executing core accounting processes and supporting the monthly close, reconciliations, and financial reporting. You will work closely with the Corporate Controller, FP&A team, and operational leaders to ensure financial activity is properly recorded and reflected in company reporting. As Mariana continues to scale, this role will also contribute to improving accounting workflows, strengthening internal controls, and helping implement systems that support efficient and reliable financial operations. This role is ideal for someone who enjoys detailed work, solving accounting challenges, and building efficient processes in a fast-moving environment.

## What You’ll Do

- Support the monthly, quarterly, and annual close process
- Prepare journal entries, accruals, and account reconciliations
- Maintain general ledger accuracy across multiple entities
- Assist with preparation of financial statements and supporting schedules
- Track and record expenses, and operational transactions
- Partner with FP&A to ensure accurate budget vs. actual reporting
- Investigate and resolve accounting discrepancies and variances
- Support implementation and documentation of accounting policies and procedures
- Assist with external audits, tax filings, and compliance requirements
- Identify opportunities to improve accounting processes and automation

Desired Qualifications

- 3–6 years of experience in accounting, public accounting, or a related role
- Strong understanding of GAAP and core accounting principles
- Experience supporting month-end close processes
- Public accounting background preferred
- Experience working with ERP or accounting systems
- Strong attention to detail and organizational skills
- Ability to manage multiple priorities in a fast-paced environment
- Strong communication skills and ability to work cross-functionally
- Background in natural resources, energy, infrastructure, or other capital-intensive businesses is a plus
- Willingness to be in the office most days and work closely with operational teams

Our culture is built on four principles:

Everyone Gets Home Safe. We never put speed or cost ahead of people. Extreme Ownership. We take full responsibility for outcomes, relentlessly driving toward solutions. Engineer Out Requirements, then Automate. We simplify, optimize, and then automate for scale. Share Your Legos. We collaborate openly, share knowledge, and empower each other to build bigger, better solutions.

Join us as we build the future of responsible mineral sourcing and supply!

## About Mariana Minerals

## Company Overview
- **One-liner**: Mariana Minerals is a software-first, vertically integrated minerals company focused on supplying the minerals critical to modern energy, AI, and defense technologies.
- **Entity Type**: Private (Series A, $85M funding in July 2025)
- **Headquarters**: San Francisco, California, United States
- **Founded**: Not publicly available
- **Founders**: Turner Caldwell (Co-Founder & CEO)

## Core Business
- **Primary industry**: Metal Ore Mining / Critical Minerals
- **Target customers**: B2B – energy, AI, and defense supply chains (including downstream manufacturers and government entities)
- **Mission or purpose**: "Create a future of critical mineral abundance" by reimagining the global minerals supply chain with software, automation, and data-driven decision making.

## Products & Services
- **Copper One (formerly Lisbon Valley Copper Mine)**: World’s first autonomous mine, located in Utah. Produces copper using integrated automation and software control. Restarted production in April 2026.
- **Lithium One**: Lithium project (on the roadmap or early development).
- **Other mineral projects**: Graphite, Uranium, Rare Earth Metals, Cobalt, Nickel, Aluminium – at various stages (stealth or roadmap).
- **CapitalProjectOS**: Internal software platform for capital project management (mentioned in leadership bio).
- **Technology Stack**: React, dbt, TypeScript, Python, TensorFlow, PyTorch, microservices, SCADA, Autodesk, and many others – indicating a strong software engineering backbone.

## Market Standing
- **Valuation/Market Cap**: Not disclosed (private company)
- **Key Metric**: Total funding – $85M Series A (July 2025, 1 investor)
- **Notable Investors/Partners**: Lead investor not publicly disclosed (Andreessen Horowitz was pitched but not confirmed as an investor). Partners include Bot Auto, WeRide, Pronto, Atoms (based on LinkedIn mentions). Also works with UMA (Utah Mining Association).
- **Growth Signals**: Headcount grew 3,575% YoY to 107 employees (as of mid-2026). 73 active job postings. Opened the world’s first autonomous mine (Copper One) in April/May 2026, generating significant industry news and social media engagement.

## Competitive Advantages
- **Software-first approach**: The company builds automation and data systems from the ground up, rather than layering tech onto legacy mining operations. This enables fully autonomous mining.
- **Vertical integration**: They develop, own, and operate mineral projects, controlling the entire value chain from extraction to processing.
- **Deep tech stack**: Use of AI/ML (TensorFlow, PyTorch), simulation, and real-time control systems to optimize mining operations.
- **First-mover in autonomous mining**: Copper One is claimed to be the world’s first autonomous mine, giving them a significant lead in operational efficiency and safety.

## Strategic Focus
- Scale autonomous mining operations beyond copper (lithium, graphite, uranium, etc.)
- Secure domestic supply of critical minerals for U.S. energy, AI, and defense needs.
- Continue aggressive hiring across engineering, operations, and field roles.
- Expand from Utah to additional sites (Houston engineering office, potential new projects).

## Why Work Here
- **Culture principles**: "Extreme Ownership", "Engineer Out Requirements, Then Automate", "Share Your Legos" – emphasizing accountability, simplification, and collaboration.
- **Work environment**: High-growth startup with a mission-driven focus on critical infrastructure. Offices in San Francisco (HQ), Houston (Engineering), and La Sal, Utah (mine site). Hybrid/remote policy not explicitly stated, but multiple office locations suggest flexibility for field vs. office roles.
- **Notable perks**: Opportunity to work on cutting-edge autonomous systems and AI in a traditional industry. Strong engineering culture with modern tech stack (React, Python, ML). Rapid career growth due to company expansion.
- **Talent sources**: Attracts talent from Tesla, Redwood Materials, Lilac, ExxonMobil, Amazon Web Services, and other tech/energy companies – indicating a high-caliber peer group.

## Sources
1. [marianaminerals.com](https://marianaminerals.com/)
2. [marianaminerals.com/careers](https://marianaminerals.com/careers)
3. [marianaminerals.com/about](https://marianaminerals.com/about)
4. [jobs.ashbyhq.com/marianaminerals](https://jobs.ashbyhq.com/marianaminerals)
5. [linkedin.com/company/mariana-minerals](https://www.linkedin.com/company/mariana-minerals)

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